Background and aimsAn international expert consensus statement was released on 2020 that non-alcoholic fatty liver disease (NAFLD) should be replaced by metabolic associated fatty liver disease (MAFLD) and hepatic steatosis (HS) is fundamental for the diagnosis of MAFLD in the new set of criteria. While female breast cancer has surpassed lung cancer as the most commonly diagnosed malignant tumor and shares the same risk factors with HS and MAFLD, but their prevalence in breast cancer survivors (BCS) is unknown. Herein, we employed the liver ultrasound elastography (USE), a more sensitive detector for HS diagnosis, to explore the more accurate prevalence of HS and MAFLD among BCS.MethodA total of 263 BCS with conventional liver ultrasonography (US) and USE tests, followed up in the clinic of the Breast Cancer Center of Chongqing, as well as age and sex matching controls (1:10) with US test, from 135,436 healthcare population in the Quality Control Center of Health Examination of Chongqing of the First Affiliated Hospital of Chongqing Medical University, were enrolled. Both US and USE were implemented to diagnose HS. Afterwards the anthropology information and relative laboratory test results were collected to estimate the prevalence of MAFLD based on USE and US according to the 2020 international consensus.ResultsThe prevalence of HS detected by US in BCS was significantly higher than that in healthcare population (41.8% vs. 22.4%, P<0.001), and it rose to 69.6% when the BCS were screened by USE. Accordingly, the prevalence of MAFLD based on US in BCS was also significantly higher than that in healthcare population (39.5% vs. 21.2%, P<0.001) and it rose to 63.5% when the BCS were screened by USE. The prevalence of HS and MAFLD based on US in elderly BCS (≥60 yr) were obviously higher than those in healthcare population (56.7% & 56.7 % vs. 31.3% & 30.7%, P<0.001), respectively, and they rose to 80.0% and 73.3%, respectively when the BCS were screened by USE.ConclusionHS and MAFLD prevail in breast cancer survivors, especially in most of the elderly breast cancer survivors (≥60 yr). Their prevalence are much higher than in the general population. Early prevention, diagnosis and treatment of HS and MAFLD in breast cancer survivors should be implemented.